Drug-Resistant Staph a Growing Problem

June 21, 2006 -- A drug-resistant form of the bacteria that causes staph, Staphylococcus aureus, has been rapidly spreading worldwide and might become an even bigger problem in the future, researchers report online in The Lancet.

The drug-resistant bug can cause infections in various parts of the body. While most aren't serious, some can be life-threatening.

Millions around the world are already infected with the drug-resistant strain, which is spread by contact with infected people or contaminated objects. Those with weak immune systems and living in hospitals, nursing homes, and other health care centers are most vulnerable.

The scientists behind the Lancet report have been studying methicillin-resistant Staphylococcus aureus (MRSAMRSA), named for the antibiotic methicillin. They include Hajo Grundmann, MD, of the Centre for Infectious Disease Epidemiology in the Netherlands.

The researchers call for countries to step up their MRSA surveillance and prevention efforts, especially in hospitals, saying infections have been "swiftly increasing worldwide over the past decades." If certain strains of MRSA take root in communities, "the MRSA situation in hospitals, which still remains out of control in many countries, could potentially become explosive," Grundmann and his colleagues warn.

About MRSA

Staph itself is a very common – and often harmless -- infection. Only a small fraction of those with staph have the drug-resistant kind.

"Of the expected 2 billion individuals carrying S. aureus worldwide, conservative estimates based on either Dutch or U.S. prevalence figures would predict that between 2 million and 53 million carry MRSA," write Grundmann and colleagues.

But MRSA's resistance to antibiotics can make it a serious, difficult-to-treat,problem.

The bacteria was discovered in 1961 and is now resistant to the antibiotics methicillin, amoxicillin, penicillin, and oxacillin. While it doesn't resist all drug treatments, it's been quick to adapt to new ones.

MRSA infections are most common among people with weak immune systems living in health care centers. Infections can appear around surgical wounds or invasive devices, such as catheters or implanted feeding tubes.

But MRSA has also shown up in healthy people who haven't been hospitalized, in what is called community-acquired MRSA.

Community-acquired MRSA is relatively rare. If it becomes common, it could worsen hospitals' MRSA situation, Grundmann's team predicts.

"MRSA is at present the most commonly identified antibiotic-resistant pathogen in many parts of the world, including Europe, the Americas, North Africa, the Middle East, and East Asia," write Grundmann and colleagues.

Since countries don't monitor MRSA, Grundmann's team made their own global estimate, coming up with the 2 million to 53 million figure.